More than 30% of responders to the World Trade Center (WTC) disaster continue to experience significant medical and/or psychiatric problems in spite of the extensive clinical services offered by the WTC Health Programs. Moreover, 20% of these patients are burdened by both mental and physical illnesses. The two signature health sequelae of the WTC disaster, post-traumatic stress disorder (PTSD) and lower respiratory symptoms (LRS) are highly comorbid. Psychiatric conditions, such as PTSD, exacerbate physical illness and increase treatment non-compliance, morbidity and mortality. The persistence of PTSD and LRS in WTC responders underscores the fact that our best efforts thus far are not sufficient, and, thus, new treatments are needed. To date, no behavioral intervention has been conducted with WTC responders to aid in the management of both PTSD and LRS. Mind-body treatments are cost-effective, efficacious treatments for comorbid mental-physical health problems in the short and long-term. The Relaxation Response Resiliency Program (3RP) is one of the leading and innovative mind-body treatments developed at Harvard by Dr. Herbert Benson and colleagues to reduce psychiatric and physical symptoms. Thus, we propose to adapt the 3RP to WTC responders and test its efficacy for simultaneously reducing PTSD and LRS in a randomized controlled trial. The aims of the current proposal are to (1) compare the effects of the 3RP versus a Health Enhancement Program on PTSD and LRS immediately post-intervention and at 3, and 6 months post intervention; (2) to evaluate the effects of the new interventions on medication usage, occupational and psychosocial functioning, and health service utilization through follow-ups; and, (3) to evaluate the effects of the 3RP versus the Health Enhancement Program on respiratory functioning (as assessed by spirometry), blood pressure, and pro-inflammatory markers immediately post-intervention and at 3 and 6 months post-intervention. We will use multimodal assessments including self-report, structured clinical interviews, daily in vivo electronic monitoring of medication use and skills practice, and biological immune and inflammation markers. We expect that the 3RP will not only simultaneously reduce PTSD and LRS but will facilitate improvements in functioning, proper medication use, and health service utilization. This treatment will also result in improved biological markers of stress and inflammation. Thus, we will be able to directly evaluate the impact of these biological markers on disease course and psychosocial changes. If this study confirms our predictions, it will be possible to implement the 3RP at other WTC-Health Program sites easily and inexpensively. Moreover, this study will be groundbreaking, as it is the first randomized clinical trial to evaluate the effects of a mind-body treatment on comorbid PTSD and respiratory illness.